1. Field of the Invention
The present invention relates to a composite structure of wood and reinforced concrete. It also relates to a composite girder including a composite structure of wood and reinforced concrete. It also relates to a dome shaped load bearing structure including such composite structure of wood and reinforced concrete.
2. DESCRIPTION OF THE PRIOR ART
At the present time there is generally the requirement to use materials of wood in an increased manner for halls, hangers and other supporting structures having long spans. A known building procedure includes the use of girders of laminated wooden boards having large cross sections at high surface loads. Forces encountered in such structures are highly concentrated. This concentration can lead to problems at joints and junctions because the magnitude of allowable forces at joints and junctions of wooden structures is limited. Further known are framework or lattice, respectively, structures which, however, necessitate complicated and intrinsic jointing elements. Wooden structures pose, furthermore, the problem that the individual elements of the structure must be laid out prior to the final assembling in order to allow the dimensions of the individual members and of the bores to be exactly matched to each other for the mutual connections. These procedures are intrinsic and time consuming and need a large precision. And in spite thereof it is still necessary to make further adjustments during the final assembly and building.
Structures made of reinforced concrete are known for a long time, including their advantages and drawbacks. The drawbacks of such reinforced concrete structures are the need to construct corresponding time and cost consuming intrinsic false works and that the structures themselves are of a large weight.
SUMMARY OF THE INVENTION
It is, therefore, a general object of the invention to provide a composite structure, in which the respective advantages of wooden constructions and reinforced steel constructions complete each other in such a manner that it is possible to design therewith building structures having small momentums of their own weight, without complicated false works and without high demands regarding precise dimensions of the individual members or elements, respectively.
A further object is to provide a composite structure of wood and reinforced concrete which comprises structural members of wood and structural members of reinforced concrete and interconnecting members which interconnect the structural members of wood and the structural members of reinforced concrete and are arranged in such a manner that they project through the cross sections of the structural members of wood and are molded into at least one cross section of reinforced concrete. Yet a further object is to provide a composite girder having a composite structure of wood and reinforced concrete including structural members of wood and structural members of reinforced concrete and interconnecting members which interconnect the structural members of wood and the structural members of reinforced concrete and are arranged in such a manner that they project through the cross sections of the structural members of wood and are molded into at least one cross section of reinforced concrete, which composite girder comprises an upper plate made of reinforced concrete, and at least one girder of laminated wooden boards at its bottom side, which at least one girder of laminated wooden boards is mounted by means of fitted set bolts to the plate made of reinforced concrete or to longitudinal ribs made of concrete formed at the plate made of reinforced concrete.
Yet a further object is to provide a dome shaped load bearing structure including a composite structure of wood and reinforced concrete having structural members of wood and structural members of reinforced concrete and interconnecting members which interconnect the structural members of wood and the structural members of reinforced concrete and are arranged in such a manner that they project through the cross section of the structural members of wood and are molded into at least one cross section of reinforced concrete, and having at least one tension arch structure of a catenary shape resting at its respective ends on the supports, which tension arch structure comprises as structural members of wood tension spars extending in the direction of the arch, which tension spars include tension plates at tension junctions, between which tension plates a respective disc of reinforced concrete is located, which tension junctions or tension spars, respectively, are anchored by means of fitted set bolts at said disc of reinforced concrete.
The connection between the structural members of wood themselves or between the structural members of wood and the structural members of reinforced concrete is made by fitted set bolts which as such are already known. The wooden members, into which initial bores for these fitted set bolts have previously been made, can be connected in a force locked manner to a body of reinforced concrete preferably after the assembling and the mounting of the bolts in that concrete is poured into the corresponding cross sections. The advantage of this procedure and design is, among others, that any deviations regarding dimensions at the structures of wood and of the earlier made bore holes for the fitted set bolts are taken up by the concrete. A preferred embodiment includes respective twin cross section members and reinforced concrete arranged between such members such that the portion of wood which swells and also which shrinks can be reduced to less than half. Furthermore, it is possible to adjust the connection to the forces to be connected or transferred, respectively, by selecting the number of cross sections which are equipped with fitted set bolts. A further advantage is that at junctions of members connecting forces occur which act only in the direction of the fibers of the wood. Accordingly, it is possible to connect the structural members of wood by a simple design also for relatively large forces.
The composite structure design finds use for various structures or building structures, respectively.